AD9910 No Output

Hi Sarmad ,

Here’s a quick guide to help you control the board externally.

By default, the board is set to output through the filtered output. If you prefer to use the unfiltered output, you can check the resistor configuration and make the necessary adjustments.
Feel free to reach out if you have any questions or need further assistance!

All the best,

Jules

Hi Jules

Thanks for sharing the guide. I am able to make it work with GUI but unable to do so using external MCU. For external control I have tried the following:

1. I earlier used a third party AD9910 board and successfully used the DRG mode to output frequency sweep. This AD9910 board was interfaced with Nucleo board. Now I am using the same Nucleo board and firmware to interface with ADI's AD9910 evaluation board.

2. I have set jumper W1-W6 as per the user guide of EVB.

3. Have connected W7 to REF_CLK and connected J1 to function generator, outputting Sinusoid of 40 MHz. Have stuffed the Loop filter components as well.

4. I have connected CSB, SCLK, SDO, SDIO, DRHOLD, DRCTL, DROVER, IO_UPDATE, MASTER_RESET signals with MCU and have grounded IO_RESET and EXT_PWR_DWN.

5. Have confirmed the SPI and control signals on oscilloscope. They are being output as intended.

6. I have tried disconnecting the 3.3 V VCC to ADI board as well.

7. The AD9910's current draw when I try to program and 40 MHz output of Function generator is enabled:

8. I have copied the configuration register values from GUI as well.

The fact that same firmware working with third party AD9910 board but fails here is really troubling. Can you please guide, what could be the issue?

Hi Sarmad ,

I also do not see any problems as your SPI lines are responding correctly. This might be only minor issue. 

I'm thinking the way it was interfaced on your external MCU. Some things worth checking:

1. May I know your register settings? I would like to check might be there are CFR1 and CFR2 registers that might have powered down the DAC. 

2. SPI settings, Mode for CPOL =0, CPHA =0, test by reading a register (like CFR1) to confirm communication.

3. Check if the frequency tuning word was loaded. Send IO_Update after writing registers.

All the best,

Jules

1. Register configuration:

2. I am using SPI Mode 0. However the read back returns 0x00000000 or 0x00103000. Tried reading several registers all read back the same value. Surprisingly, I read back data on SDO line.

3. I checked PLL_LOCK pin, and it is at low level. SYNC_CLK outputs 5 MHz clock.

If I keep clocking in more than 64 bits without toggling the chip select signal, will the data shift out on SDO pin?

If I keep clocking in more than 64 bits without toggling the chip select signal, will the data shift out on SDO pin?

Hi Sarmad ,

I have checked your register settings and have observed the following:

1. Single tone output used. 

2. Used Profile mode, with Profile 0. 

3. Used amplitude dithering.

4. Kept RAM, modulation engines, and sweeps inactive

And I cannot see any problems or register settings that might have triggered this. 

Just wanted to check if you have seen the issue resolved or still on the verge of getting a solution? Apologies for the late response. 

All the best,

Jules

I am still unable to resolve the issue. Earlier I was probing at microcontroller connecter. Now I am probing at U5 connector on the eval. board and I read-back these values:

Hi Sarmad ,

I was trying to check your hardware connections. Is the Vcc on your TB1 connected to a 3.3V source? Connecting J1 to signal generator. Start a power sequence as follows: turn on power supply, turn on signal generator RF output. 

When you probed at U5, which pins did you probe? 

All the best,

Jules